News
28 Oct 2013

Quick as a flash

Tiny light-sensitive crystal may hold the key to refining the world’s smallest machines.

UV light rearranges the atoms within the crystal, building up strain, a bit like compressing a spring and so when released, the crystal leaps, as viewed from above.Credit: Wiley-VCH

It might be one small hop for a crystal, but this light-responsive material looks like one giant leap forward for miniature machines.

Researchers at New York University’s Abu Dhabi campus have discovered millimetre-sized, cobalt-based crystals that jump up to a metre across the room when ultraviolet light is shone on them.

Materials that move in response to light are not new but their responses are typically small and slow. The jumping crystals have explosive speed. Pance Naumov and Elena Boldyreva are now working to harness the crystals inside devices. The fast-responding materials could find uses from tiny valves on lab-on-a-chip medical tests to powering tuneable optical elements for cameras.

Naumov admits they are unsure exactly what makes the crystals jump. What they do know is that light rearranges the atoms within the crystal, building up strain, a bit like compressing a spring, and when released it leaps. Warming the crystal restores its original structure, readying it to leap again.

James Mitchell Crow is deputy editor of COSMOS.